CrossWorks for ARM User Guide

If x < -1 or 1 < x, and y = +Infinity, pow returns +Infinity.If x < -1 or 1 < x, and y =-Infinity, pow returns 0.If -1 < x < 1 and y = +Infinity, pow returns +0.If -1 < x < 1 and y = -Infinity, pow returns +Infinity.If x = +1 or x = -1 and y = +Infinity or y = -Infinity, pow returns NaN.If x = +0 and y > 0 and y NaN, pow returns +0.If x = -0 and y > 0 and y NaN or y not an odd integer, pow returns +0.If x = +0 and y 0 and y NaN or y not an odd integer, pow returns +Infinity.If x = -0 and y is an odd integer, pow returns -0.If x = +Infinity and y > 0 and y NaN, pow returns +Infinity.If x = +Infinity and y < 0 and y NaN, pow returns +0.If x = -Infinity, pow returns pow(-0, y)If x < 0 and x Infinity and y is a non-integer, pow returns NaN.Portabilitypow conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).powfSynopsis#include float powf(float x, float y);Description powf computes x raised to the power y.Fast math librarybehaviorIEC 60559 mathlibrary behaviorIf x < 0 and y 0 and y NaN or y not an odd integer, powf returns +0.If x = +0 and y 0 and y NaN or y not an odd integer, powf returns +Infinity.If x = -0 and y is an odd integer, powf returns -0.If x = +Infinity and y > 0 and y NaN, powf returns +Infinity.Chapter 28 - Mathematics271